Objetivo: o objetivo deste estudo foi avaliar a prevalência de autoanticorpos e a dosagem da concentração de células Natural Killer (NK) no sangue periférico em pacientes com endometriose. Métodos: Entre dezembro de 2004 e dezembro de 2007 foram avaliadas 155 pacientes submetidas a videolaparoscopia, divididas em um grupo sem endometriose(n=55) e outro com endometriose (n=100). Foi coletada amostra de sangue periférico de todas as pacientes no momento da laparoscopia e nessa amostra foi realizada a quantificação do percentual de células NK em relação aos linfócitos periféricos (por citometria de fluxo), e a determinação dos seguintes auto-anticorpos: anticorpos antinucleares (ANA, por imunofluorescência indireta), anticorpos antitireoglobulina e antiperoxidase (anti-TG e anti-TPO, por eletroquimioluminescência), anticorpos anticardilipina e antifosfatidilserina (aCL e aPS IgG, IgM e IgA, todos por ensaio imunoenzimático). Além da presença de endometriose, essas pacientes também foram avaliadas quanto ao estadiamento, os locais de doença, relações com a fase do ciclo, e a classificação histológica dessa doença. Resultados: as pacientes com endometriose apresentaram percentual de células NK (média DP de 15,3 9,8%) superiores àquelas sem a doença (média DP de 10,6 5,8%), p<0,001. Quanto aos autoanticorpos, as portadoras de endometriose também apresentaram positividade para ANA mais frequentemente (33%) que as pacientes do grupo controle (12,7%), p=0,006. Quanto aos anti-TG, anti-TPO, anti-CL (IgG, IgM e IgA) e aPS ( IgG, IgM e IgA), não houve diferenças estatísticas quanto à sua positividade. As células NK também mostraram-se mais elevadas nas protadoras de endometriose em estádios avançados e naquelas com comprometimento de retossigmóide, grupo no qual encontramos o maior percentual de células NK com concentração média de 19,8 10,3%. Concentrações de células NK 12,5% podem ser usadas como marcadores de endometriose em retossigmóide, com sensibilidade de 73% e especificidade de 65%. Utilizando-se de um modelo estatístico de probabilidades, demonstramos que associação desse marcador (NK 12,5%) com a presença de sintomas como dor e/ou sangramento intestinal durante a menstruação nos possibilitou estimar uma probabilidade de comprometimento de retossigmóide de 60,4%. Conclusões: pacientes com endometriose apresentam maior concentração de células NK periféricas, além de maior prevalência de ANA positivo em relação àquelas sem endometriose. As células NK aumentam nas pacientes com endometriose predominantemente nos estádios avançados, com comprometimento de retossigmóide. Nesse sentido poderiam ser utilizadas como marcadores diagnósticos desse tipo de comprometimento da doença, principalmente se forem avaliadas em conjunto com os sintomas das pacientes

Objectives: The objective of this study was to evaluate the prevalence of autoantibodies and the percentage of natural killer (NK) cells in the peripheral blood of patients with endometriosis. Methods: Between December 2004 and December 2007, 155 patients submitted to videolaparoscopy were evaluated. Patients were divided into two groups: one group of women without endometriosis (n = 55) and another in which all the women had endometriosis (n = 100). Samples of peripheral blood were collected from all the patients at the time of laparoscopy and flow cytometry was used to determine the percentage of NK cells in relation to peripheral blood lymphocytes in these samples. In addition, the following autoantibodies were measured: antinuclear antibodies (ANA) by indirect immunofluorescence, anti-thyroglobulin and anti-thyroid peroxidase antibodies (anti-TG and anti-TPO) by electrochemiluminescence, and anticardiolipin and anti-phosphatidylserine antibodies (aCL and aPS IgG, IgM and IgA), all performed using immunoenzymatic assay. In addition to the presence of endometriosis, these patients were also evaluated with respect to staging, to the sites of the disease, any association with the phase of the menstrual cycle and the histological classification of the disease. Results: The patients with endometriosis had a higher percentage of NK cells (15.3 ± 9.8%; mean ± SD) compared to those without the disease (10.6 ± 5.8%; mean ± SD), (p<0.001). Evaluation of the autoantibodies showed that positivity for ANA was more common in the group of patients with endometriosis (33%) compared to the patients in the control group (12.7%), (p = 0.006). With respect to anti-TG, anti-TPO, aCL (IgG, IgM and IgA) and aPS (IgG, IgM and IgA), no statistically significant differences were found between the groups of patients with or without endometriosis. NK cell concentrations were also found to be higher in patients with advanced stages of endometriosis and in those in whom the rectosigmoid was affected by the disease, this being the group in which the highest percentage of NK cells was found, with mean concentrations of 19.8 ± 10.3%. NK cell concentrations 12.5% may be used as markers of endometriosis of the rectosigmoid, with sensitivity of 73% and specificity of 65%. Using a statistical model of probability, these findings showed that the association of this marker (NK 12.5%) with the presence of symptoms such as pain and/or intestinal bleeding during menstruation permitted an estimation to be made of a likelihood of 60.4% of rectosigmoid endometriosis. Conclusions: Patients with endometriosis have higher percentages of peripheral NK cells, as well as a greater prevalence of positive ANA compared to those without endometriosis. The concentration of peripheral NK cells increases in patients with endometriosis, predominantly in patients with advanced stages of the disease and those in whom the rectosigmoid is affected. Therefore, the concentration of NK cells in peripheral blood could be used as a diagnostic marker of this type of endometriosis, particularly when evaluated together with patients symptoms